1. Field of the Invention
The invention relates to machines for cutting vegetation, and more particularly, to machines for clearing dense, heavy vegetation, including small trees, cutting the vegetation into small chips or pieces, and removing the chips or pieces.
2. Description of the Prior Art
A variety of machines have been proposed for cleaning dense vegetation from land. In some cases, dense, undesirable vegetation grows around right-of-ways, railroads, highways, and various other places where it poses safety and/or health hazards. In other instances, it is necessary to remove dense brush and/or small trees from land in order to make it useful for other purposes, such as farming, building, pipe lines, power lines, etc. In some cases, dense brush, small trees, and the like can be economically harvested to provide the basic materials for making alcohol or to supply chips for making pulp for the paper and compressed board industries. In the past, such land clearing has often been accomplished by means of crawler-type tractors, using dozer blades or chains or hand-held power saws. Many types of vegetation harvesting machines are well known for harvesting conventional crops, such as corn. However, none of the crop harvesting machines are capable of attacking dense brushwood or tree-like vegetation. One type of vegetation clearing unit disclosed in U.S. Pat. No. 3,972,158 discloses an attachment which can be connected to a large articulated tractor. The attachment has five laterally disposed disc-shaped cutting blades with toothed cutting edges which extend forwardly of the housing to form an unbroken cutting line. The tractor merely moves forward, forcing the cutting blades at the bases of brush and trees. The blades rotate so as to move the severed brushwood and vegetation sideways, clearing a path for the tractor to progress along. However, the device does not chop the severed vegetation into chips or remove the brush or trees once they are cut. Separate time consuming and labor consuming operations involving different utilization of different pieces of heavy and expensive equipment are required to remove the cut vegetation and chop it into chips suitable for shipment to and use by various industries, such as the pulp making industry or the alcohol industry. Another clearing machine for brushwood is disclosed in U.S. Pat. No. 3,996,980, and discloses a pair of rotary cutters having sickle-shaped cutting edges which capture brushwood to be cut and move it along stationary blades having the appearance of a giant sawtooth to produce a prolonged slicing action. The weight of the cut brush falls upon the sickle-shaped cutting blades, which rotate in opposite directions, tending to feed the severed brushwood into a chopper, which produces chips. The entire unit is attachable to a tractor. The unit has an overhead framework which extends forward of the cutting blades, and tends to push tall shrubbery forward before it is reached by the cutting blades.
Neither of the above described machines is suitable for economically clearing land of heavy vegetation which includes dense brush and small to medium sized trees. Although the device disclosed in U.S. Pat. No. 3,972,158 is indeed capable of cutting trees having large trunk diameters, this does not solve the other problems described above. The cutting blades of the device disclosed in U.S. Pat. No. 3,996,980 would easily become jammed if rocks or wood material having hardness or size exceeding predetermined hardness or size is encountered by the cutting blades. Further, the slicing action results in rapid dulling of the cutting edges. The device of U.S. Pat. No. 3,996,980 is suitable only for cutting relatively small brushwood and very small, flexible trees. Reliance upon the rotating action of the cutting blades to feed the cut brushwood, etc., into the chopper produces relatively unreliable operation.
Accordingly, it is an object of the invention to provide a machine for clearing land, which machine is capable of severing unflexible tree trunks, as well as dense, heavy brushwood and converting the severed trees and brushwood into small chips capable of being blown by a blower unit into a suitable container for subsequent utilization.
Another object of the invention is to provide a vegetation clearing machine which more efficiently cuts and conveys dense brushwood and medium sized trees into chips easily useable by the wood pulp and alcohol industries.
Yet another object of the invention is to provide a vegetation clearing machine which conveys initially severed brushwood and trees into pieces which are of more suitable size for ingestion by a high speed chopper unit than the clearing machines of the prior art.
Still another object of the invention is to provide a vegetation clearing machine which, after severing brushwood, trees and the like, conveys the cut vegetation to a high speed chopper more efficiently than prior vegetation clearing or harvesting machines.
A further object of the invention is to provide a machine for clearing heavy brushwood and small to medium sized trees from land and reduce the cut material to small chips, which machine overcomes the shortcomings of the known prior art.
A novelty search directed to the present invention uncovered, in addition to the two previously mentioned patents, the following patents: U.S. Pat. Nos. 2,477,794, 3,673,774, 4,098,060, and 3,919,830. These patents all disclose harvesters for harvesting stalk-type crops. Various combinations of conveyers, cutters, and augers for cutting and conveying stalk-type crops, such as sugar cane or corn, are disclosed. However, none of the disclosed machines would be suitable for clearing heavy brushwood and the like.